In recent years, for diagnosis of biomedical tissue, there has been proposed an optical coherent tomography (OCT: Optical Coherent Tomography) device which can obtain optical information of the inside of tissue, other than an imaging device which can obtain information of a surface condition of the tissue. An optical coherent tomography device is a technology that low coherence light is divided into two beams, one of the beams is projected to a subject, back scattered light on which phase information of the subject has been given interferes with the other beam, the phase information of the subject is obtained based on intensity information of the inferring light, and an image of a measuring portion of the subject is formed (see Patent Literatures 1 and 2, for example).
In Patent Literature 1, for the purpose of making a penetration catheter penetrate a proper position, a mark is provided on an area of an optical probe of an optical coherent tomography device and the image of the mark is observed, which enables to adjust the position and/or rotation direction of the leading end of the probe.
Patent Literature 2 provides an intraluminal image forming device which uses a probe for being inserted into a lumen to obtain a tomographic image, for observing the inside of the lumen and taking its image with moving the probe in a guide tube. In the intraluminal image forming device, a mark is provided on the guide tube to determine a reference position of a tomographic image, and imaging process is performed without image displacement.